A wide variety of control systems and methods have been developed for improved automotive ignition system operation and efficiency, including now well known distributorless ignition systems. Such systems and methods have increasingly employed electronic control means, including microprocessors with various peripheral devices, or more completely packaged microcontrollers.
Electronic distributorless ignition systems typically include multiple ignition coils wherein each coil energizes at least one corresponding spark plug.
The ignition coils are generally organized into multiple groups, or banks, with various input/output (I/O) devices relaying signals to and from the ignition coil banks.
Microprocessor or microcontroller based control systems and methods for such distributorless ignition systems typically include a memory for storing the signals relayed to and from the ignition coil banks by the I/O devices. Such memory also stores the software responsible for processing and generating the signals in order to implement the ignition control method.
Such microprocessor or microcontroller based ignition control systems and methods are exemplified by U.S. Pat. Nos. 4,913,123 issued to DeBiasi et al; 4,625,704 issued to Wheelock; and 4,558,684 issued to Caddy et al. Moreover, microprocessor or microcontroller based ignition control systems and methods provide advantageous means to control multiple ignition coil banks independently thereby allowing sequential ignition coil charging periods to overlap. In turn, such overlapping dwell provides for now well known ignition system benefits, as described in U.S. Pat. No. 5,014,676 issued to Boyer, including repetitive spark capability and no reduction of spark energy as engine speed increases.
However, as efforts to improve automotive ignition system efficiency continue, the software necessary for microprocessor or microcontroller based ignition control systems and methods has become increasingly more complex. More complex software, in turn, uses more of the finite and valuable memory space provided in commercially available microprocessors or microcontrollers. As available memory space decreases, the ability of microprocessor or microcontroller based control systems and methods to control additional and more complex aspects of ignition systems also decreases. As automotive ignition systems themselves become more complex, memory space availability, unaddressed by the aforementioned references, becomes increasingly problematic.